Various prosthetic repair materials have been proposed to reinforce the abdominal wall and to close abdominal wall defects. Marlex mesh, a single bar warp knit, dual course Atlas polypropylene monofilament knit, is exemplary of an implant material that has been successfully used in hernia repair. Traditionally, prosthetic repair materials are placed in an open procedure where a two inch or longer incision is made through the abdominal wall, layers of healthy tissue are retracted to expose the void and then the rupture is filled or covered with the implantable fabric.
Recently, prosthetic surgical fabrics have been implanted laparoscopically which is a surgical procedure employing slender tubes (cannulas) that extend through narrow punctures in the abdominal wall. Because the abdominal cavity remains closed, the surgeon employs an illuminating optical instrument through one of the cannula to visualize the surgical site on a television monitor. Surgical instruments are manipulated by the surgeon through other cannula in the abdominal wall, as the location of the instruments are observed on the monitor, to place the prosthetic repair material over or in the defect.
A concern has been raised that light may reflect off of the fabric surface during laparoscopy, potentially impairing visualization of the prosthetic repair material and the underlying anatomy. Increasing the pore size of a mesh fabric may improve laparoscopic observability but also may diminish the physical properties that had suggested the implant for augmenting or repairing abdominal wall defects. Many large pore mesh fabrics are known, such as the various openworks described in Paling, Warp Knitting Technology (Columbine Press). Although a dual bar warp knit, hexagonal mesh is described by Paling in FIGS. 67f, 74 and 75 and at page 114, there is no indication or suggestion that such a fabric would be suitable as a prosthetic or that it would obviate the potential laparoscopic visualization concern.
Accordingly, there is a need for a mesh fabric suitable for hernia repair which combines the performance and physical characteristics of conventional prosthetic repair materials with good laparoscopie visibility.